Dicyclopentadiene dicarboxylic acid-cross-linked cellulosic textiles which may be durably creased or uncreased due to chemical bond reformation under heating conditions



United States Patent 0 3,547,574 DICYCLOPENTADIENE DICARBOXYLIC ACID- CROSS-LINKED CELLULOSIC TEXTILES WHICH MAY BE DURABLY CREASED OR UNCREASED DUE TO CHEMICAL BOND REFORMATION UN- DER HEATING CONDITIONS William E. Franklin, Charles H. Mack, and Stanley P. Rowland, New Orleans, La., assignors to the United 7 States of America as represented by the Secretary of Agriculture No Drawing. Filed Sept. 13, 1968, Ser. No. 759,792 Int. Cl. D06m 13/20, 13/22; C08b 13/12 U.S. Cl. 8120 2 Claims ABSTRACT OF THE DISCLOSURE A cellulosic textile material is reacted with a difunctional dicyclopentadiene wherein the functional groups are any cellulose reactive groups to produce a material which may be durably set in a given configuration under heating conditions.

A nonexclusive, irrevocable, royalty-free license in the invention herein described throughout the world for all purposes of the United States Government, with the power to grant sub-licenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to new cellulosic derivatives.

This invention also relates to a process for imparting to cellulosic textiles a novel physiochemical characteristic, said characteristic comprising the ability of the cellulosic textile product to accept a durable and reformable physiochemical configuration by submitting the new cellulosic derivative to heat molding. This invention also relates to a process involving chemical modification of cellulosic materials with a specific type of reagents which upon crosslinking the cellulose with the reagent a new quality is imparted wherein reversible thermal dissociation of the cross-links of the derivatives can be accomplished. The physiochemical configurations and the quality of accepting new configurations are durable to ordinary washing and ironing. Also, the wrinkle-resistant cellulosic textiles produced by the process of this invention can be converted into garments, and the like, where in use it may be desirable to be able to introduce or remove a crease, or a pleat, or other selected configuration at will, and as many times as necessary to reestablish the chosen configuration. The products of the instant invention are more specifically difunctional dicyclopentadiene crosslinked derivatives of cellulose.

In reference to nomenclature applicable to the instant invention, the system of naming the pertinent organic compounds can be understood readily upon referring to the Definitive Rules for Nomenclature of Organic Chemistry, published in the Journal of the American Chemical Society, volume 82, p. 5545 (1960).

The first object of the instant invention is to provide novel textile treating compositions, methods, and treated textiles capable of accepting imparted creases, pleats, or other selected deformations.

The second object of the instant invention is to provide textiles :with the potential of accepting selected deformations which can be removed and reshaped without further chemical treatment.

In the state of the art it is known that wash-and-wear and wrinkle resistant finishes for use on cellulosic fabrics are based on covalently bonded crosslinks joining the cellulose molecules within the fibers. The establishment of the crosslinks binds the fiber and, therefore, the fabric into the configuration present at the time of cross-linking. Because of the covalent character of the cross-links the conventional cross-linking processes permanently set the cellulosic fabric in one configuration. The permanently set configuration of cross-linked cellulosic fabrics despite its desired effects, imparts certain undesirable properties to the treated fabrics; i.e., the permanent cross-links make it impossible to impart durable creases, pleats, or other deformations to the fabric after the finishing process is complete. It is, therefore, impossible to impart sharp durable creases or flat seams to garments manufactured from cross-linked cellulosic fabrics.

In sifting the prior art one finds a patent issued on Oct. 25, 1960 (U.S. Pat. 2,957,746) which describes the introduction of creases into cross-linked cellulose fabrics by the use of acidic catalysts for the hydrolysis and reformation of N-methylol-type cross-links.

Breaking cross-links by means of chemical reactions involving strong acids or alkalis and reforming the crosslinks in the creased or otherwise deformed fabric is not practical for tailors, dressmakers, or housewives. Such treatment of complete garments by manufacturers is not practical because of the added time and extra steps and equipment required for such processes. The strong chemical treatment required to break the covalent cross-links has detrimental effects on the quality of the retreated fabric.

An article entitled, Deferred Cure Process for Durable Press, appeared in the American Dyestutf Reporter, pp. 28-31 (Aug. 1, 1966). This article describes a process which has been labeled the Koratron Process and is described as a process which locks the crease in the pressed condition during the curing step.

Delayed cure processes overcome some of these disadvantages in the use of cross-linked cellulosic fabrics, but several important disadvantages remain. Although permanent creases and flat seams may be permanently set by use of delayed cure techniques, the resulting garments cannot be altered, permanently set creases cannot be removed, and new durable creases cannot be imparted to the garment after the curing step is completed.

Cellulose in the form of fibers can be reacted with compounds containing several different types of functional groups to produce cellulose derivatives having the different types of groups attached to the cellulose chain by covalent bonds. Among the types of functional groups which can react with cellulose are the following: carboxylic acids and derivatives of carboxylic acids such as acyl halides and anhydrides; alkyl halides, sulfates, and other alkylating agents; organic epoxides; N-methylol amides, N-methylol amines, N-methylol carbamates, and other like N-methylol compounds; compounds containing reactive double bonds, such as vinyl sulfones, acrylic acid derivatives; and other compounds containing functional groups capable of reacting with organic hydroxyl groups. The article entitled Preparation and Evaluation of Selected Aliphatic Acid Ester of Cotton Fabric is presented by Cruz-Lagrange et al. in the American Dyestuif Reporter, volume 51, No. 12, pp. 40-42 (June 11, 1962) and deals with monofunctional carboxylic acids which cannot form. cross-links.

Compounds containing two functional groups, which may be the same or different. and which are both capable of reacting with cellulose, can be used to introduce covalent crosslinks into cellulose. The preparation and evaluation of cellulosic esters with good resiliency caused by diester cross-links which are stable to heat is disclosed by Campbell et al., in The Crosslinking of Cotton Cellulose by Alipahatic Dicarboxylic Acids in the Textile Research Journal, volume 35, pp 260-270 (1965 Also, is is well known that dicyclopentadience and most compounds containing the dicyclopentadience or tricyclo [5,2,l,0 ]deca 3,8 diene carbon skelton dissociate when heated to high temperatures to form two molecules of monomeric cyclopentadiene or cyclopentadiene derivatives. It is also known that the cyclopentadiene or derivatives of cyclopentadiene redimerizes at lower temperature to give the original dicyclopentadiene or dicyclopentadienc derivative or isomers of the original dicyclopentadiene having the tricyclo[5,2,l,0 ]deca- 3,8-diene carbon skelton. Examples of compounds which undergo this reversible thermal dissociation include diccyclopentadiene, methyl cyclopentadiene dimer and other alkylated or polyalkylated cyclopentadiene dimers, esters of the isomeric dicyclopentadiene dicarboxylic acids, diacyl chlorides of the dicyclopentadiene dicarboxylic acids, bis(dialykylamides) of the dicyclopentadiene dicarboxylic acids and isomeric dicyanodicyclopentadienes. A related disclosure which might be pertinent to the instant invention can be found in an article by the authors of the instant invention. The article which is entitled. Dissociation and Diels-Alder Reactions of Dicyclopentadienedicarboxylic Esters, is found on pages 626 and 632 of volume 33 of the Journal of Organic Chemistry and was published in February of 1968. This article is concerned with the dissociation of dimenthyl esters of dicyclopentadienedicarboxylic acids and contains a review of the information in the literature concerning the structures and the dissociations of methyl esters of dicyclopentadienedicarboxylic acids.

We have now discovered that cellulose can be crosslinked with certain difunctional derivatives of dicyclopentadiene wherein each potential cyclopentadienyl group is monofunctionally attached to cellulose. Unexpectedly we have found that these crosslinks are capable of dissociating when the cellulosic derivative prepared by our method is subjected to a high temperature, and that said cross-links have reassociated by the time that the said cellulosic derivative has cooled.

Durable configurations, fiat or contoured, creased or pleated, may be imparted to or removed from cellulosic fabrics containing these cross-links by constraining the fabric in the desired creased or other configuration and applying heat for a suflicient quantity of time to allow the crosslinks to dissociate and reassociate in the altered configurations.

Substantially any cellulosic material containing hydroxyl groups can suitably be employed in the present process. Illustrative examples of such materials include cellulose derived from cotton, flax, ramie and the like vegetable materials, wood cellulose, regenerated cellulose such as viscose rayon and the like, partial esters of cellulose such as partially acetylated cellulose and the like, and partial ethers of cellulose such as partially cyanoethylated cellulose and the like. In general, the cellulosic textile fibers, in the form of free fibers, slivers, yarns, threads, or fabrics, including natural fibers and partial ethers or partial esters thereof which are produced by reactions in which the fibers retain their cellulosic textile properties, are preferred starting materials. The cellulose textile fibers in the form of spun textiles, i.e., yarns, threads, or cloths, are particularly suitable starting materials.

The crosslinking agent may be any compound containing the dicyclopentadienyl (tricyclo[5,2,l,() ]deea-3,8- acyl halide group, and the carboxylic anhydride group; capable of reacting with cellulosic hydroxyl groups, one of which is attached to each of the two potential cyclopentadienyl fragments of the carbon skelton and having the formula 1 CH /I \2 3 9 CH 10 CH--CH H CH2 I ll 8 CH X011 4 Bi H C 2\ where in R and R are functional groups capable of re acting with cellulosic hydroxyl groups and which may be the same or different. Group R is substituted for any one of the hydrogen atoms bonded to any of the carbon atoms numbered 1, 7, 8, 9, or 10 in the formula above the group R is substituted for any one of the hydrogen atoms bonded to any of the carbon atoms numbered 2, 3, 4, 5, or 6 in the formula above.

The groups R and R may be any functional groups capable of reacting with cellulosic hydroxyl groups and forming a covalent bond with the cellulose molecule. Examples of such groups include the carboxylic acid group and its derivatives such as the ester group, the acyl halide group, and the carboxylic anhydride group; reactive methylol groups such as the N-methylol amide group and the N-methylol cambamate group; groups containing reactive double bonds, such as the vinyl ketone group and the vinyl sulfonyl group; epoxy groups such as the glycidyl group and the epoxyethyl group, alkyl halide groups such as the chloromethyl and the like organic halides; and other groups capable of reacting with cellulose to form ether, ester, or other covalent bonds with the cellulose molecule. The dicyclopentadienyl carbon skelton may also be substituted with one or more non reactive groups, such as methyl or other alkyl groups.

The cross-linking agent must be capable of dissociating thermally and reversibly after it is attached to cellulose. It is not necessary that the reassociation of ,the dissociated cross-links give the same structure as the original crosslink, but the reassociated cross-links must have the dicyclopentadienyl carbon skelton. An example of such a dissociation and reassociation is given in the following formula, but this should not be construed to limit the scope of the invention in any way:

Our preferred cross-linking agents are dicyclopentadienedicarboxylic acids and their derivatives. These crosslinking agents may be any of the isomeric dicyclopentadienedicarboxylic acids having one of the carboxy groups on each of the potential cyclopentadiene portions of the dicyclopentadienyl carbon skeleton. Examples of such dicarboxylic acids are 4,9 dicarboxyltricyclo[5,2,l,0, deca-3,8-diene (I) and 1,4 dicarboxyltricyclo[5,2,l,0, deca-3,8-diene (II).

I CH\ HO2CC i OIL-CH:

H 2 H CH\ Cg C" C 021 C 0112 II 302E: OH: I CH'-CH H 2 ll C& /CH /C--C 0211 CH CH2 Nonfunctional derivatives of these acids having one or more methyl, other alkyl or other nonreactive groups substituted for one or more of the hydrogen atoms bonded to the dicyclopentadienyl carbon skeleton are also suitable dicarboxylic acids for this invention. These dicarboxylic acids may be reacted with cellulose as the free acid, or

they may be converted to suitable functional derivatives such as the acyl halides or mixed anhydrides before they are reacted with cellulose.

Any of the reactions usually employed in the preparation of cellulose esters may be used to crosslink cellulose with the dicarboxylic acids of this invention. Examples of such reactions include the reaction of carboxylic acids with cellulose in the presence of an impeller such as trifluoroacetic anhydride, trichloroacetic anhydride, dichloroacetic anhydride, or chloroacetic anhydride; the reaction of an acyl halide with cellulose in the presence of a solvent and acid acceptor such as pyridine alone or pyridine and dimethylformamide; the reaction of a solution of an acyl halide in an inert solvent such as carbon tetrachloride with the sodium or other metal salt of cellulose; and other like esterification methods. Substantially any apparatus usually employed in the esterification of cellulose can be employed.

The esterification may be allowed to proceed to any convenient degree of substitution of ester groups on the d cellulose anhydroglucose units which gives desirable textile properties to the cellulosic material. In general degrees of substitution from 0.01 to 0.50 are convenient for the crosslinking agents of this invention. The concentration of the dicarboxylic acid or diacyl chloride in the esterification solution may be any convenient value, but concentrations between 0.05 molar and 0.50 molar are preferred for convenient time of reaction and extent of reaction. The ratio of moles of dicarboxylic acid or diacyl chloride per mole of anhydroglucose unit during the esterification may vary from 0.05 to 3.0, but the preferred ratio is 0.20 to 0.60 mole of dicarboxylic acid or diacyl chloride per mole of anhydroglucose units. The reaction may be allowed to proceed for any convenient time, and the temperature may vary from room temperature to the reflux temperature of the solvent. In general, it is preferred to allow the reaction to proceed for three to forty-eight hours and to carry out the reaction at room temperature to C.) if the rate of esterification at this temperature is suificiently rapid to be practical.

The preferred reaction for esterification of dicyclopentadienedicarboxylic acids with cellulose is the reaction of the free dicarboxylic acid with cellulose in the presence of an impeller such as trifiuoroacetic anhydride. The reaction may be carried out in any inert, nonaqueous, nonhydroxylic solvent which does not react with trifluoroacetic anhydride, but which does dissolve the mixed anhydride between the dicarboxylic acid and trifiuoroacetic acid and allows intimate contact of the cellulosic fibers with the esterification solution. Suitable solvents include benzene, toluene, and similar aromatic solvents; hydrocarbon solvents such as hexane and heptane; chlorinated solvents such as carbon tetrachloride and chloroform; and the like solvents. If the solvent does not dissolve the dicarboxylic acid, the dicarboxylic acid and the trifiuoroacetic anhydride impeller should be mixed with the solvent and the mixture should be agitated until the dicarboxylic acid has been converted to the mixed anhydride and gone into solution. It is preferred to employ at least two moles of trifluoroacetic anhydride for each mole of dicarboxylic acid. A slight excess of trifluoroacetic anhydride is particularly preferred. It is inetficient and uneconomical to use a large excess of trifluoroacetic anhydride. The cellulosic material used in this process must be free from water, and best results are obtained if the cellulosic textile is in the swelled condition. Our preferred method is to swell the cellulosic textile in warm or hot water, then to remove the water by several solvent exchanges with anhydrous methanol, followed by several solvent exchanges with anhydrous benzene or other solvent used in the esterification.

The esterification employing the preferred reaction is conducted in such a manner that the solution of the esterifying agent has free access to all parts of the textile. Our preferred method of conducting the reaction is to roll the swelled and solvent-exchanged fabric with loosely woven glass cloth and place it in the previously prepared solution of the dicarboxylic acid and trifluoroacetic anhydride in the solvent. The container is tightly closed and the reaction is allowed to stand with occasional agitation for the desired time of reaction.

After the desired time of reaction, the esterification solution is removed from the fabric and the fabric is thoroughly washed with l) the solvent, (2) warm water, and (3) boiling methanol. The thorough washing is necessary to remove traces of trifiuoroacetic acid which would otherwise remain on the cellulosic fabric and cause slow degradation of the cellulose.

Durable creases, pleats, or other deformations are imparted to the esterified fabric prepared according to this invention by heating the fabric while it is constrained in the desired configuration. The fabric may be heated at temperatures varying from C. to 185 C. The preferred temperature is to C. Lower temperatures require longer periods of heating, while higher temperatures cause excessive weakness or brittleness in the fabric. The fabric may be heated by any convenient method. Examples of such methods include immersing the constrained fabric in a solvent held at desired temperature and heating the constrained fabric in an oven, in air or in vacuum. The fabric may be constrained in the desired configuration by any convenient method which permits the fabric to be heated at the desired temperature for the desired time. An example of such a method is to press the fabric between two glass or metal plates held together by spring clamps. The fabric may be heated for periods of time from 10 minutes to 5 hours. The preferred time of heating is 30 to 90 minutes. Shorter times produce less sharp creases and longer times produce excessive discoloration and weakness in the fabric.

Yarns of cellulosic fibers treated according to this invention may be durably coiled or otherwise deformed by heating them while they are constrained in the desired coil or other configuration. For example, yarns may be durably coiled by wrapping them around rigid rods and heating them. The temperatures and times of heating are the same as those described for fabrics.

Fabrics creased or otherwise durably deformed by the process of this invention may be uncreased or the configuration may be otherwise durably altered by constraining them in the flat or other desired new configuration while they are heated under the conditions described above for the durable deformations. Yarns, which have been durably coiled or otherwise deformed by the process of this invention, may likewise be uncoiled or otherwise deformed into a new configuration by constraining them in the new configuration and again heating them under the conditions described above for the durable deformations.

The durability of fabric deformations produced by this invention is established by a crease retention test. Samples of fabric 1.5 by 2.0 cm. are cut before or after washing such that a 1.0 by 1.5 cm. area of fabric is on each side of the crease to be tested. The fabric sample is washed in running water at 60 C. for two hours. The fabric sample is spread with the crease open and allowed to dry as flat as possible. The creased fabric sample is spread open with the inside of the crease on a flat, smooth surface and covered with a 500 g. weight for 60 seconds to press it fiat under standard conditions. The fabric sample is turned over and one side of the sample is placed on a fiat horizontal surface with a 5 g. weight arranged to keep that side of the fabric sample fiat and horizontal, while the other side of the sample extends upward. After the fabric sample has been allowed to relax for 60 sec. the angle between the two sides of the sample is measured and reported as the crease retention angle (CRA). An uncreased fabric sample thus has a CRA of and a creased sample has a lower CRA. In general, a CRA much less than 180 indicates a sharp crease. The durability of the crease is furter tested by ironing the creased fabric sample flat for sec. with the iron on the cotton setting. The CRA is again measured as before.

In summarizing the crux of the instant invention, the invention can best be described as a plurality of cellulosic derivatives with novel characteristics, and the process for preparing these. These derivatives are prepared by a process for preparing chemically cross-linked cellulosic derivatives, textiles made thereof containing a configuration which is set upon subjecting the said textile to a select temperature for a correspondingly select period of time compatible with the time required for the set of the particular textile material, whose thcrmoset configuration is reformable upon subjecting the said cross-linked cellulosic derivative to the said heat set treatments, whose reformable quality can be utilized repeatedly, said quality being durable to washing, whose reformable textile configuration is due to the effect of the high temperature upon the dicyclopentadiene ring and specifically the rupture of the bridge system, and whose general chemical formula is wherein X can be the linkage from dicyclopentadiene to cellulose selected from the group consisting of ester, N- methylolamide, ether, and sulfonyl ethyl, wherein the weight increase of the chemically modified cellulosic derivative is in the range of about from 6.5% to 9.6%, the preparation of the derivative comprising:

(a) Reacting a cellulosic textile with an organic agent of the said general structure,

(b) Washing and drying the cellulosic derivative, and

(c) Thermoforming the washed and dried cellulosic derivative to a selected configuration.

The following list of examples is presented to illustrate the invention and is not meant to limit its scope in any manner whatever.

EXAMPLE 1 A sample (18" x 11", 18.0 g.) of 80 x 80 cotton fabric (desized, scoured, and bleached) was heated in water at 90 C. for 90 minutes, then washed four times in anhydrous methanol and four times in anhydrous benzene and rolled into a cylinder in loosely woven glass cloth. The fabric sample was placed in a solution prepared from 6.6 g. of dicyclopentadiene dicarboxylic acids (a mixture of 1,4-dicarboxyand 4,9-dicarboxytricyclo[5,2,1,0 deca-3,8-dienes, prepared by the addition of a solution of cyclopentadienyl sodium in tetrahydrofuran to a mixture of Dry Ice and xylene), 17 ml. of trifiuoroacetic anhydride, and 125 ml. of anhydrous benzene and contained in a tube fitted with a ground glass stopper. The tube was securely closed, shaken for ten minutes, and allowed to stand with occasional shaking for twenty hours at room temperature.

The reaction solution was poured from the esterified fabric and the fabric was thoroughly washed with benzene, acetone, water, boiling methanol, and water again. The fabric was ironed dry. The esterified fabric had an add-on of 6.6% and a conditioned wrinkle recovery of 139 (warp only). Unmodified cotton fabric of this type generally has a wrinkle recovery of 60 to 85 (Warp only).

The reaction of a sample of the esterified fabric with excess silver o-nitrophenoxide solution, followed by titration of the excess reagent, showed that the fabric had 0.037 free carboxy groups per anhydroglucose unit. A modified Eberstadt titration showed that the fabric had a total of 0.124 free and esterified carboxy groups per anhydroglucose unit. There were thus 0.025 cross-linking dicyclopentadienedicarboxylate units per anhydroglucose units.

EXAMPLE 2 The procedure of Example 1 was followed with the exceptions that 3.3 g. of pure 4,9-dicarboxytricyc1o[5,2,1,

o u 0 ]deca-3,8-diene, 5.2 ml. of trifiuoroacetic anhydride, and 5.7 g. of cotton were used and that the reaction was allowed to proceed for 48 hours. The add-on was 9.6% and the wrinkle recovery was 132 (warp only, conditioned).

EXAMPLE 3 The procedure of Example 1 was followed with the exceptions that 9.9 g. of cotton, 3.3 g. of mixed dicyclopentadienedicarboxylic acids, and 10.4 ml. of trifluoroacetic anhydride were used and that the reaction was allowed to proceed for 68 hours. The add'on was 7.3% and the wrinkle recovery was 144 (warp only, conditioned). Titrations showed that the esterified fabric had 0.036 free carboxy groups per anhydroglucose unit, 0.113 total free and esterified carboxy groups and 0.028 cross-linking dicyclopenadienedicarboxylate groups per anhydroglucose unit.

EXAMPLE 4 A 4-cm. by 6-cm. piece of cotton fabric prepared according to Example 1 was folded so that the crease was along the length of the piece and the warp yarns were creased. The folded fabric was placed between two glass plates held together by means of spring clamps. The assembly was heated in an oven at 16 C. for two hours. The fabric sample was removed from the glass plates, washed with agitation for minutes in water at 60 C., spread open and allowed to dry. The crease retention angles were found to be to before ironing and to 132 after ironing.

A piece of cotton fabric prepared according to Example l with the exception that adipic acid was substituted for dicyclopentadienedicarboxylic acid was cr. ased for 2 hours at 160. The crease angle of this sample was l68169 before ironing, and after ironing the crease had completely disappeared.

A piece of unesterified cotton was creased at 160 for 2 hours. This sample had a crease angle of 166 170 before ironing, and after ironing the crease had completely disappeared.

EXAMPLE 5 Nine fabric samples prepared according to Example 1 were creased according to Example 4, except that they were heated in the oven for different times. Table 1 shows the time of heating, the crease retention angle before ironing and the crease angle after ironing.

EXAMPLE 6 A sample of fabric prepared according to Example 1 was treated according to Example 4, except that it was heated at 145 C. for 180 minutes. The crease angle before ironing was 113 to and after ironing 127 to EXAMPLE 7 A piece of cotton fabric prepared according to Example 1 and creased for 2 hours at was spread open and clamped flat between two glass plates. The assembly was heated in the oven at 160 for 150 minutes. The crease angle of the fabric was 173 and no crease was present after ironing.

EXAMPLE 8 The following experiments were performed in order to further establish the fact that the ability of the cellulosic derivatives of this invention to retain a thermoset configuration is the result of the reaction of cellulose 'with the difunctional dicyclopentadiene derivatives of this invention and in order to establish the durability of the thermoset configurations to repeated flexing or other distortions.

A yarn (26.5 cm. length) removed from 80 x 80 cloth treated according to Example 1 was tightly wound on a 2.4 mm. diameter steel rod and heated in the oven at 150 C. for three hours. The yarn was then removed from the rod, soaked in distilled water ,for four hours, and allowed to dry overnight while suspended from one end and stretched by a 3.0 g. weight attached ,to the other end. The length of the stretched yarn was'measured and the weight was removed. After the yarn had relaxed into a coil while still suspended from one end for four hours, the length of the coiled yarn was again measured. The stretched, uncoiled length was found to be 172% of the coiled, relaxed length.

The yarn was subjected to repeated cycles of stretching and relaxation in groups of first 50 cycles while the yarn was dry, then 50 cycles while the yarn was immersed in water, then 50 cycles dry, etc. After 350 cyc'les of stretching and relaxation, the stretched length was found to be 139% of the relaxed coiled length.

A yarn from adipate crosslinked cotton fabric was coiled and'heated in the same manner. This yarn had a stretched length of 116% of the relaxed, slightlytoiled length. After 50 cycles (dry) of stretching and relaxation the stretched length was 104% of the relaxed length, and after another 50 cycles of stretching and relaxation (wet) the stretched length was equal to the relaxed length.

A yarn from unesterified cotton fabric was coiled and heated in the same manner. This yarn had a stretched length of 110% of the relaxed, slightly coiled length. After cycles of stretching and relaxation (dry) the stretched length was 102% of the relaxed length, and after another 50 cycles of stretching and relaxation (wet) the stretched length was equal to the relaxed length.

What is claimed is:

1. A process for preparing a cross-linked cellulosic textile material having a thermoset configuration which is durable to washing and which may be repeatedly reformed by subjecting said material to a heat setting treatment comprising:

(a) reacting a cellulosic textile material with a dicyclopentadienedicarboxylic acid until said material undergoes a weight increase based on the dry weight of the material of from about 6.5% to 9.6%,

(b) washing and drying the reacted material, and

(c) setting thedried material in a given configuration by subjecting it to a heat treatment.

2. The product produced by the process of claim 1.

. References Cited Tedder: Chemical Reviews, vol. 55, No. 5, pp. 787- 794 (1955).

Campbell et al.: Textile Research Journal, vol. 35, pp. 260270 (1965).

Franklin et al.: Journal of Organic Chemistry, vol. 33, pp. 626-632 (1968).

GEORGE E. LESMES, Primary Examiner J. CANNON, Assistant Examiner U.S. Cl. X.R. 

